Angels and Demons (2000) is a mystery novel by Dan Brown who is well known for literary techniques that are well displayed in Angels and Demons, such as mysterious investigations into conspiracy theories and explorations in corrupt religious histories. This book is the first to feature Brown's main character, Robert Langdon, who is also the main character for four subsequent books by Brown: The Da Vinci Code, The Lost Symbol, Inferno, and Origin.
In 2003, The Da Vinci Code gained public acclaim in the media and among American readers, which may have reinforced the public reception of Angels and Demons. Brown has often been criticized for his employment of historical inaccuracies and his position against the Christian/Catholic churches, but he maintains that the Langdon series is not anti-Christian. Nevertheless, the books encourage a critical view on history and faith, and perhaps even a healthy skepticism.
Angels and Demons is a book that develops thrilling scenes from epiphanies about the interconnectedness of seemingly innocuous riddles. It achieves this by way of codes, symbols, abstraction and a persuasive narrative that leads the reader to feel their own mind challenged to reckon all of the data. Secret societies, obscure codes, impossible riddles, and corruption in Angels and Demons all combine into the foundation novel for Brown's Langdon series. The main feature of this book is the use of Anagrams in an exciting way.
The story is epitomized as a power struggle between two old enemies: the Vatican and the Illuminati. At the beginning of the story, an Illuminati conspirator steals a canister containing antimatter (or dark matter) and places it in the Acropolis (crypt) beneath the Basilica San Pietro (St Peter's Basilica). Not only is it a power struggle, but an allusion to the millennia-old debate between science and religion.